"As a member of the Senate Armed Services and Intelligence Committees, I believe any expanded U.S. military role beyond airstrikes in the fight against ISIL in Iraq must be approved by Congress,” Udall said in a statement, using an alternative term for the Islamic State in Iraq and Syria.

“The American people must be assured that we are not pursuing another open-ended conflict in the Middle East, and I will not give this president — or any other president — a blank check to begin another land war in Iraq,” Udall said. “As we have seen in the past, American boots on the ground cannot stamp out an extreme ideology, and the Iraqis must take responsibility for defending their own people.”

He, like every Democrat who weighed in Wednesday, said he plans to continue to demand further details from the administration on its plans.

Begich, one of four Democratic incumbents running for reelection in a red state, said, while he supports airstrikes, he’s opposed to arming rebels.

“I oppose the President’s plan to arm Syrian rebels at this time. I am gravely concerned by reports of ISIS seizing and utilizing U.S. weapons intended for those fighting against the Syrian regime, and we must have greater assurance that we aren’t arming extremists who will eventually use the weapons against us,” he said.

“The U.S. can't continue to foot the bill of Middle East conflicts and the nations in the region need to step up in a meaningful way. After over a decade of costly war, many Alaskans are rightfully wary of putting combat troops on the ground.”

Begich also said, “we need to step up our efforts to secure our homeland” to prevent ISIS from entering the country at its borders.

Shaheen, who has faced attacks from Republicans calling her a rubber stamp for Obama, said, while “outlining a strategy tonight was a start,” she will press the administration for further details on its plans going forward.

“In hearings next week, I intend to question Administration officials on their plans to implement this strategy to confront the full scale of the terrorism challenge we face, particularly in Syria,” she said. “And as I have made clear, I will continue to press the President to use all of the tools at his disposal, short of ground combat troops, to defeat ISIS."

Her Republican opponent, former Massachusetts Sen. Scott Brown, has focused heavily on the ISIS threat over the past few weeks, charging Obama’s foreign policy, which he says Shaheen supports, has contributed to the situation.

Franken struck a similar tone to Shaheen’s, pledging to act in an oversight role in the Senate, and Pryor expressed support for destroying “these terrorists with decisive and targeted airstrikes.”

“Tomorrow, the Senate will be briefed by national security officials, and I plan to ask them a number of questions,” Franken said. “I want to find out more about the potential ramifications of these actions on the civil war in Syria, for more specifics about the coalition the administration intends to build, and about their ongoing efforts to stifle terrorist recruitment activities in Minnesota and around the country.”

Hagan largely seemed to agree with Obama’s proposed plan, declaring, “as long ago as the spring of last year, I pressed the Administration to arm and empower moderate Syrian rebels and I am glad that effort will be accelerated.”

And Hagan, who represents a state with a heavy military population, suggested she would ultimately support any legislative measures meant to give support to military action against ISIS.

“This is the time for us to come together, Democrats and Republicans, to confront the challenges that are facing our nation. I will continue working with my colleagues in Congress to provide the support that our military requires and deserves,” she said.

The issue is politically fraught for Democrats, as support for military action risks alienating progressive Democrats opposed to an aggressive, hasty response, like the one that launched the Iraq War, which is now seen by many as a quagmire. But polling has shown Americans overwhelmingly support military action, and are expressing higher levels of fear and concern for their safety than they have in recent memory, increasing the pressure to act.

And the division within the party underscores the challenge Congress faces in rallying behind a passable proposal for military action against ISIS.